Question: Simplify the following expression: $k = \dfrac{6x + 8y}{10y + 6z} - \dfrac{4y}{10y + 6z}$ You can assume $x,y,z \neq 0$.
Solution: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{6x + 8y - (4y)}{10y + 6z}$ $k = \dfrac{6x + 4y}{10y + 6z}$ The numerator and denominator have a common factor of $2$, so we can simplify $k = \dfrac{3x + 2y}{5y + 3z}$